PS8502-AX Optoisolator Equivalent & Substitute Parts

Part Overview

The PS8502-AX is a 5000Vrms optoisolator with transistor output manufactured by CEL in an 8-DIP through-hole package. This component provides galvanic isolation for single-channel DC input applications with a maximum output current of 8mA per channel. The PS8502-AX is discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives that maintain electrical and mechanical compatibility for existing designs.

Substiute Parts

PS8502-AX

CELIn Stock: 2258PS8502-AX Datasheet

Current PartRFQ

HCPL4503M

onsemiIn Stock: 6122HCPL4503M Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the PS8502-AX is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Voltage isolation rating of 5000Vrms
• Single-channel configuration
• Transistor output topology
• Maximum output voltage of 20V or greater
• Output current capability of 8mA or greater
• DC input type
• Current transfer ratio minimum of 15% or greater

Mechanical Compatibility Requirements:

• 8-DIP package with 0.300" (7.62mm) pitch
• Through-hole mounting
• Pin-compatible footprint

Compliance Requirements:

• ROHS3 compliance
• REACH unaffected status
• EAR99 classification

The HCPL4503M from onsemi meets all electrical and mechanical compatibility criteria for direct substitution in the PS8502-AX application space.

Parameter Comparison

Engineering Selection Recommendations

The HCPL4503M is a direct functional substitute for the PS8502-AX in applications where the following conditions are met:

Voltage Considerations: The HCPL4503M has a maximum output voltage rating of 20V compared to the PS8502-AX at 35V. Applications requiring output voltages exceeding 20V are not suitable for this substitution.

Temperature Range: The HCPL4503M operates from -40°C to 100°C, compared to the PS8502-AX range of -55°C to 100°C. Applications requiring operation below -40°C require the original PS8502-AX or alternative parts with extended low-temperature ratings.

Performance Advantages: The HCPL4503M provides a higher minimum current transfer ratio (19% versus 15%) and lower forward voltage (1.45V versus 1.7V), resulting in improved efficiency and faster switching characteristics (250ns/260ns versus 220ns/350ns).

Compliance Status: Both parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory compatibility in equivalent applications.

Product Availability: The HCPL4503M is active in production with 6080 units in stock, providing supply continuity for the discontinued PS8502-AX.

Frequently Asked Questions (FAQ)

Q: Can the HCPL4503M replace the PS8502-AX in all applications?

A: The HCPL4503M is compatible with PS8502-AX applications that do not exceed 20V output voltage and do not require operation below -40°C. Verify your circuit's voltage and temperature requirements before substitution.

Q: What is the difference between transistor output and transistor with base output?

A: The PS8502-AX provides standard transistor output. The HCPL4503M provides transistor with base output, offering an additional base connection for enhanced circuit design flexibility. This difference does not prevent substitution in standard applications.

Q: Are the packages physically identical?

A: Both parts use 8-DIP packages with 0.300" (7.62mm) pitch and through-hole mounting. Pin-to-pin compatibility is maintained for direct PCB substitution.

Q: What are the key electrical differences between these parts?

A: The HCPL4503M has a higher current transfer ratio minimum (19% versus 15%), lower forward voltage (1.45V versus 1.7V), and lower maximum output voltage (20V versus 35V). These differences result in improved input efficiency but reduced output voltage capability.

Q: Do both parts meet the same compliance standards?

A: Both the PS8502-AX and HCPL4503M are ROHS3 compliant and REACH unaffected. They share identical ECCN (EAR99) and HTSUS (8541.49.8000) classifications.

Q: What is the moisture sensitivity level of the HCPL4503M?

A: The HCPL4503M has a moisture sensitivity level of Not Applicable, compared to the PS8502-AX at MSL 1 (Unlimited). This indicates the HCPL4503M has no moisture sensitivity restrictions.